"A Radiological Dispersion Devise, or "dirty bomb", is a mix of explosives with radioactive powder or pellets. When it explodes the blast scatters radioactive material. (1) A dirty bomb is not the same as an atomic bomb, which produces an atomic mushroom cloud. (2) A dirty bomb cannot create an atomic blast. It uses dynamite or other explosives to scatter radioactive materials which cause radioactive contamination.... The terrorists' purpose is to spread fear. The main danger from a dirty bomb is the explosion, which can cause serious injuries and damage. The radioactive materials in a dirty bomb would probably not lead to enough radiation exposure to cause serious illness immediately, except to those people who are very close to the blast site. However, the radioactive dust and smoke that spreads could be dangerous to health if they are inhaled". (FEMA, "Fact Sheet - Dirty Bombs" (FEMA 573), NIMS Integration Center, June 2007, p. 1)